There are three principles that guide Islamic inheritance. The first, are the tiers of relationship to the deceased; so, the closer in relation, the higher they are in line to receive without regard to gender. The second, is the beneficiary’s generation rank within life; so, a daughter will always receive more than her grandparents or uncles without regard to gender because of the potential needs in life. Finally, is the overall financial responsibility that is expected from the beneficiary according to the rules of Islam.
A major misconception that has arisen, is that Islam discriminates in the issue of inheritance based on gender. This misconception can be dispelled as the Quran does not mention that females will always receive half of the amount that a man will receive. Additionally, a female will receive an equivalent amount to a man in many situations. Ex.: if an adult son passes and the parents are in the line of inheritance along with his children, each of the parents will receive an equal share of 1/6th. There are many situations that follow this same path.
Also note that there are many cases in which a female will receive more than the men in her family. Ex.: if a father were to pass away leaving 2 daughters, a father, and brothers; the 2 daughters will receive 2/3rd of the estate, and in this same case if he only had one daughter, she would have half of the estate and all other surviving family would split the remainder of the estate according to inheritance rules.
In some cases, women will receive a share of the inheritance when her male counterpart will not. Ex.: in the case of maternal grandparents; the grandmother will receive a share where the grandfather will not.
Those who present allegations of discrimination base their arguments on a case where there are a surviving son and daughter. Ex.: The father passes away and leaves one son and one daughter. Note that we have only 4 situations in the entire rules of inheritance where a female will receive half of what her male counterpart will. The above example is one of them. The reason is that the religion intends to have a holistic approach to what a person will inherit and the financial responsibilities that will be expected from them. To further expound on this thought, consider this example: if a father passed away and left $150,000 for a son and a daughter; the son will have $100,000 and the daughter $50,000. Islam requires that the brother take care of his sister financially before marriage and if she were to be divorced. Also, when the son will marry he will be required to take care of his family, where the daughter will be at the receiving end and her husband-to-be will be responsible for their expenses. So, in the end, the brother’s inheritance will most likely be depleted and the sister’s will mostly remain.